查看文章

Generally, only B lymphocytes express immunoglobulin. Recently, we found the expression of Ig alpha heavy chain in human epithelial cancer cells unexpectedly. We first detected Ig VDJ-Cα and Iα-Cα transcripts in multiple cancer cell lines. Further, the configuration of the Ig heavy chain genomic locus was analyzed in human cancer cells. We found that cancer cells have the recombination VDJ region, but bear Ig Sα region in germline configuration, which is different from Ig expression pattern in B cells. And human epithelial cancers possess the essential effectors including RAG-1 and RAG-2, but not activation induced cytidine deaminase (AID) protein. These provide further proofs for Ig alpha expression. In addition, we found that human cancer cells not only express the protein of Ig alpha chain, but also secrete the protein in secretory IgA (SIgA) pattern. Importantly, diverse CDR3 recombinations were found in …